Water in Living Things
Discover how much water is in your body and food
Setting up the bench…
What this lesson covers
Why it matters
Your blood, a plant's sap, the sea — life runs on water because it dissolves so much. But not everything: oil floats, sand sinks.
Predict first
Why is water called the 'universal solvent'?
Water dissolves many substances (salt, sugar, even oxygen) — that's how it carries nutrients in blood and sap. But oils, sand and chalk don't dissolve.
- It dissolves a huge range of substances, carrying nutrients through living things — correct
- It can dissolve absolutely everything
- It is the heaviest liquid
What you do
Sort each: does it dissolve in water, or not?
Check yourself
Why is water vital inside living things?
As a solvent, water dissolves nutrients and gases and transports them through blood and sap.
Which of these does NOT dissolve in water?
Oil is insoluble — it floats in a separate layer. Salt and sugar dissolve.
- It dissolves and carries nutrients around the body — correct
- It has no taste
- It is blue
- Cooking oil — correct
- Salt
- Sugar